Human rhinoviruses, coxsackieviruses, hepatitis A viruses, and hepatitis C viruses are commercially important. RiboGene, Inc. has established an in vitro screening system to identify compounds that inhibit translation of virus-specific gene products. Phase I funding will be used to establish screening systems for coxsackievirus, hepatitis A virus, and hepatitis C virus, analogous to a rhinovirus screening system already established. Mass screening of natural product extracts and defined chemical entities for agents that inhibit translation of these viruses will also begin in Phase I. Human rhinovirus, coxsackievirus, hepatitis A virus, and hepatitis C virus translation systems are excellent targets for anti-viral compounds since they are essential for viral replication and function very differently than the translation system used by most, if not all, human mRNAs. PROPOSED COMMERCIAL APPLICATION: There is currently no effective prophylactic or treatment available for rhinovirus, coxsackievirus, hepatitis A virus, or hepatitis C virus infections. Effective antivirals for these viruses would therefore fill major medical needs and have enormous potential markets.